1. Field of the Invention
The present invention relates to a one-press method for producing a glass vessel, the method involving a process of forming a parison having a finish form and cooling the parison by one-time press molding (called as one press method) to produce a glass vessel efficiently.
The present invention relates particularly to a one-press method for producing a glass vessel, the method enabling efficient production of even a glass vessel having a specific parting line which is inconspicuous and the maximum thick wall part having a thickness larger than a predetermined value.
2. Description of the Related Art
Conventionally, because glass is chemically stable and superior in transparency, it is therefore frequently used as structural materials of glass vessels and these glass vessels are produced using a forming mold. As a method for producing such a glass vessel industrially and continuously, the blow and blow molding method and press and blow molding method are known.
For example, the blow and blow molding method is a production method in which a block of melt glass called a gob is filled in a rough mold and blow air is blown in this rough mold to form a parison. Then, this parison is transferred to a finishing mold to reheat and then, blow air is blown into the parison to swell it, thereby molding the parison into the form of the finishing mold.
The press and blow molding method is a production method in which a block of melt glass called a gob is filled in a rough mold and insert a plunger into the rough mold to form a parison. Then, this parison is transferred to a finishing mold to reheat and then, blow air is blown into the parison to swell it, thereby molding the parison into the form of the finishing mold.
However, the blow and blow molding method and the press and blow molding method have the feature that the produced glass vessel has an inside diameter larger on the body side than on the mouth side because blow air is blown into the parison. For this, in the case of using the glass vessel by filling it with a cream-like material such as cosmetics, there is a possibility of having a difficulty in taking out the content stuck to a position close to the mouth part in the body of the glass vessel.
Also, in these molding methods, blow air is blown to press the parison against the molding surface of the mold. Therefore, the surface irregularities of the molding surface of the mold and the trace of residual air in the mold are left on the surface of the obtained glass vessel and there is therefore a possibility of having inferior qualities.
Here, with regard to the problem as to the difficulty in taking out the content, it is possible to take out the content in the vessel easily by increasing the wall thickness of the glass vessel such that the mouth part and the body of the vessel have equal diameters.
With regard to the problem concerning the formation of irregularities on the surface of the glass vessel, this problem can be avoided by preventing the surface of the parison from being in contact with the mold when molding the glass vessel.
In light of this, a method for producing a bottle is proposed, the method enabling an efficient production of a glass vessel having such a shape and a wall thickness (see Patent Document 1).
More specifically, this proposed method is a one-press method for producing a bottle, the method involving a press step of forming a parison having a finish form by inserting a plunger into a finishing mold filled with a gob and a cooling step of transferring this parison having a finish form to a cooling mold to forcedly cool the outside peripheral surface and inside peripheral surface of a parison by a second cooling air blown to the outside of the cooling mold and a first cooling air blown to the inside of the parison.
FIG. 22 shows the situation where the step of cooling the parison having a finish form is carried out.    [Patent Document 1] JP2000211930A (Claims, FIGS. 1 to 3)